| Message ID | 20121121150730.6644.99859.stgit@localhost.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
OK, applying.--b. On Wed, Nov 21, 2012 at 06:07:38PM +0300, Stanislav Kinsbursky wrote: > Protection of __nfs4_state_shutdown() with nfs4_lock_state() looks redundant. > > This function is called by the last NFSd thread on it's exit and state lock > protects actually two functions (del_recall_lru is protected by recall_lock): > 1) nfsd4_client_tracking_exit > 2) __nfs4_state_shutdown_net > > "nfsd4_client_tracking_exit" doesn't require state lock protection, because it's > state can be modified only by tracker callbacks. > Here a re they: > 1) create: is called only from nfsd4_proc_compound. > 2) remove: is called from either nfsd4_proc_compound or nfs4_laundromat. > 3) check: is called only from nfsd4_proc_compound. > 4) grace_done; called only from nfs4_laundromat. > > nfsd4_proc_compound is called onll by NFSd kthread, which is exiting right > now. > nfs4_laundromat is called by laundry_wq. But laundromat_work was canceled > already. > > "__nfs4_state_shutdown_net" also doesn't require state lock protection, > because all NFSd kthreads are dead, and no race can happen with NFSd start, > because "nfsd_up" flag is still set. > Moreover, all Nfsd shutdown is protected with global nfsd_mutex. > > Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> > --- > fs/nfsd/nfs4state.c | 2 -- > 1 files changed, 0 insertions(+), 2 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index e75872f..d41cc71 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -4926,9 +4926,7 @@ nfs4_state_shutdown(void) > cancel_delayed_work_sync(&nn->laundromat_work); > destroy_workqueue(laundry_wq); > locks_end_grace(&nn->nfsd4_manager); > - nfs4_lock_state(); > __nfs4_state_shutdown(net); > - nfs4_unlock_state(); > nfsd4_destroy_callback_queue(); > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e75872f..d41cc71 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4926,9 +4926,7 @@ nfs4_state_shutdown(void) cancel_delayed_work_sync(&nn->laundromat_work); destroy_workqueue(laundry_wq); locks_end_grace(&nn->nfsd4_manager); - nfs4_lock_state(); __nfs4_state_shutdown(net); - nfs4_unlock_state(); nfsd4_destroy_callback_queue(); }
Protection of __nfs4_state_shutdown() with nfs4_lock_state() looks redundant. This function is called by the last NFSd thread on it's exit and state lock protects actually two functions (del_recall_lru is protected by recall_lock): 1) nfsd4_client_tracking_exit 2) __nfs4_state_shutdown_net "nfsd4_client_tracking_exit" doesn't require state lock protection, because it's state can be modified only by tracker callbacks. Here a re they: 1) create: is called only from nfsd4_proc_compound. 2) remove: is called from either nfsd4_proc_compound or nfs4_laundromat. 3) check: is called only from nfsd4_proc_compound. 4) grace_done; called only from nfs4_laundromat. nfsd4_proc_compound is called onll by NFSd kthread, which is exiting right now. nfs4_laundromat is called by laundry_wq. But laundromat_work was canceled already. "__nfs4_state_shutdown_net" also doesn't require state lock protection, because all NFSd kthreads are dead, and no race can happen with NFSd start, because "nfsd_up" flag is still set. Moreover, all Nfsd shutdown is protected with global nfsd_mutex. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> --- fs/nfsd/nfs4state.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html